I think you need to go into your admin interface and check out the posted articles and such like.
I think you have something published with a blank title/article and you need to unpublish it.
Have to admit last time I used it I did not take to how things are organised and found it tricky at times to get the right section to modify.
/edit looking at it looks like links/menu section rather than a post/article but I am sure pretty much there will be something in the defined having been told to be active but lacks the essential info.